Pen clip



FIG. 1 is a front side bottom perspective view of a pen clip showing my new design, with the phantom lines depicting environmental structure and forming no part of the claimed design;

FIG. 2 is a right side elevational view thereof which is a mirror image of the left side thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a back elevational view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for a pen clip, as shown and described. 